Lubricating greases



Patented Nov. 17, 1953 PATENT OFFICE LUBRIOATING GREASES Jacob Faust, Bellcville, N. 1., assignor to L. Sonneborn Sons, Inc., a corporation of Delaware No Drawing. Application January 6, 1951,

Serial No. 204$}? H 8 Claims. (Cl. 25243.2) This invention relates to improvements in emulsion should be from about 30 to 60%. and the lubricating greases.

In the past many difficulties have arisen in the manufacture of greases in which saponification is accomplished by the use of aqueous slurries of an insoluble metal hydroxide at elevated temperatures. In such processes of manufacture the handicap of considerable quantities of water is encountered. This water is diiilcult to remove and necessitates prolonged cooking, which in 10 many cases does not efiect complete removal. The water retained after cooking is completed detracts from the eficiency of the grease and may induce corrosion of the metal surfaces to be lubricated. In the case of water-proof greases 5 the retained water may afiect the greases water resistance. Such greases have a slimy and murky appearance and develop lumpiness requiring the finished grease to be strained.

One object of this invention is to overcome the above mentioned dimculties. This and further objects will become apparent from the followin description and examples.

According to the invention a mineral lubricating oil solution of fats or fatty acids is intimately contacted with an insoluble metal hydroxide, which is dispersed throughout a water-in-oii emulsion containing a petroleum mahogany sulfonate. It is preferable that the petroleum mahogany sulfonate be of the same metal as the in- 0 soluble metal hydroxide.

The emulsion containing the insoluble metal h droxide may be prepared in any manner proded that the emulsion is not formed before the addition of the insoluble metal hydroxide. preferably formed by dissolving the petroleum mahogany sulfonate in a carrier oil, adding the insoluble metal hydroxide to form a paste, and then adding required amounts of water.

The carrier oil. 1. e., the oil used in making the emulsion, should preferably be the same mineral oil as is used in the grease. The viscosity of this carrier oil should preferably not substantially exceed 47 seconds Saybolt at 210 F. and 310 seconds Saybolt at 1M) F. Thus, if an oil having a greater viscosity is used as the base oil for the grease, a diflerent lighter oil should be used as the carrier oil. The viscosity range of the carrier oil in any case should preferably be from about 38 80-47 seconds Saybolt at 210 F. and 110 to 310 50 seconds Saybolt at 100 F.

The amount of the petroleum mahogany sulfonate used should be controlled so that the amount present in the emulsion is from about 3 Itis 35 solve the fats or fatty acids; A quantity of the emulsion, containing a substantially stoichiometric amount of the metal hydroxide in relation to the fats or fatty acid, is then added with stirring to the oil, whereup saponiflcation takes place. No heat need be supplied during saponifi cation. A smooth, homogeneous paste is formed, no lumping of the mixture occurs. and there is no water separation, as is the case in conventional grease working. All the water contained in the grease formed is contained in the internal phase.

The amount of base oil used in dissolving the fats and fatty acids varies from 5 to depending upon the type of grease, and is as high as for water pump grease, and as low as 5% for viscose pressure greases. The metal hydroxide used in accordance with the invention may be any of the metal hydroxides convention ally known and used in the production of grease. such as calcium hydroxide (lime), lithium hydroxide, barium hydroxide and strontium hy droxide. The petroleum mahogany sulfonate may be any petroleum mahogany sulfonate, but it is preferable that it be of the same metal as the metal hydroxide. Thus, when using lime, calcium petroleum sulfonate should be used. The fats and fatty acids used are those conventionally known and used in the production of greases. these being fatty acids containing between 12 and 20 carbon atoms and their glycerides.

The greases made under the new process are superior to those made in the conventional manner; for example, the consistency (ASTM worked penetration) of water pump greases made under the new process varies from about to 200 as compared to 240 to 340 for those made in the conventional manner. The retention of the consistency (ASTM worked penetration) of the same grease remains constant after six months for the grease made under the new process, while it changes to from 300 to 380 for the grease made by the conventional method. The water resistance of grease made in accordance with the invention, measured by putting a ball of the grease on the end of a thermometer placed in a 600 to 8%. The amount of water present in the 55 beaker filled with water, boiling the water and made according to the conventional method, it

drops to less than three minutes. The corrosion inhibition or the new greases excels that of the greases made according method.

The iollowing examples are given by illustration and not limitation:

EXAIMPLEI A mixture of 210 pounds of tallow fatty acids, 20 pounds of hydrofol fatty acids (hydrogenated fish oil containing 52.6% stearic acid, 42.6 palmitic acid, 3.7% myristic acid, 0.8% oleic and 3% lauric acid), and 43 gallons or mineral oil were first charged into a steam-jacketed kettle and the temperature raised to 150 F. to melt the fatty acids. Then a lime slurry obtained by stirring together 60 pounds of hydrated lime and 11 gallons of water were run in while agitating the whole mixture. Though the lime slurry was strained prior to adding it to the fatty material, lumping oi the mixture was observed. As the saponification proceeded a great quantity of water separated from the batch. amounting to 65% ot the water added. Sampling of the grease in half hour intervals showed that maximum saponification was obtained after four hours, but it requiredtwo additional hours to cock out the separated water.

Alter six hours of cooking the balance or the mineral oil (43 gallons) was stirred in. Straining or the finished grease was necessary in order to tree it from lumps. The finished grease had a mucky and slimy appearance and as comparative figures will show later, an interior consistency and water-resistance.

EXAMPLE 2 A similar grease was made, using the same amount of fatty material, mineral oil, lime and water as in Example 1, except that the'lime was added in a water-in-oil emulsion.

The latter was made by stirring the lime into an oil solution of calcium petroleum sulionate and then adding to the lime paste, the same amount or water as in Example 1. 29 pounds or a 30% solution of calcium petroleum sulionates in oil were used to prepare the lime emulsion.

Though the saponification was started with the steam completely shut oil. the mixture was observed to quickly form a smooth, homogeneous paste. There was no lumping oi the mixture and no water separation whatever. Sampling of the batch at definite intervals oi. time showed that saponification was more complete and proceeded at much faster rate at the same temperature than in the case of Example 1.

EXAMPLES EXAMPIEt A similar grease as in Example 8 was made,

way or to the conventional using same percentages or raw material, except thatalimeslurrywasusedinsteadoialime emulsion. Formation of lumps and separation or water. was observed as in Example 1. Also the properties of the finished grease were the same as or the grease prepared in Example 1.

A comparison 01' the ASTM penetration oi the grease made in Examples 1, 2, 8 and 4 is shown in Table I below; a comparison of them:-

ter-resistance made in boiling water is shown in Table 11 below. and Table III shows a comparison of the rates of saponification by showing the percentages of completion or saponification next to the indicated time.

Table I Examples 1 2 3 4 ASTM Penetration 77 F After six months Table II over 25 gver 25 Example 1 Example Example Example 4 Table III SAPONIFICATION RATE Example 1 2 Percent samurai ass reassess l Grease finished.

The finished greases of Examples 1 and 4 contained mechanically entrapped water in spite of prolonged heating, which was easily detected by slightly pressing the grease. This tree water is highly objectionable to the grease since it causes softening of the grease on standing and affects its water-prooiness. It is even more objectionable when considered from the point 01' corrosion of metal surfaces to be lubricated by the grease because each droplet 01' water forms a weak spot in the lubrication film, which form loci of corrosion or the metal.

EXALIPLE 5 A lithium grease was formed with 17.7% tallow fatty acid, 3.5% hydroi'ol fatty acid, 3.2% lithium hydroxide and 75.6% mineral oil by adding the fatty acids and lithium hydroxide slurry together with one-half of the mineral oil and heating the mixture to about 200 F. Saponification started but was not complete until the temperature was increased to about 300 F. and so maintained for about two hours. The balance of the oil was then added and the heating continued until a fluid gel had formed. To obtain this fluid gel formation the material had to be heated to about 450 F. and maintained at this temperature for an additional two hours. The finished grease had to be strained to remove the lumps.

EXAMPLE 6 hydroxide, except that the latter was used in v a water-in-oil emulsion having the composition as shown in Table IV. Saponiflcation started even before heating, and was complete after cooking for about minutes at about 230 F. The balance of the oil was then added and the heating continued to about 300 F. which resulted in a homogeneous fluid gel. The heat was then cut oil and the finished grease cooled while stirring. No straining of the finished grease was necessary.

EXAMPLE 7 Barium grease and strontium grease were prepared in the same manner as the grease prepared in Example 6, using the same oil and fatty materials as were used in Example 6, except that the emulsions used contained the saponifying materials as shown in Table IV below. The greases obtained were of similar quality as those obtained in Example 6. No lumps were formed and no straining was necessary.

1. In the method for the production of lubricating grease by saponification, the improvement which comprises intimately contacting a mineral lubricating oi1,containing a solution of at least one member of the group consisting of fats and acids thereof, with an emulsion, said emulsion being a water-in-oil emulsion containing a petroleum mahogany sulfonate dissolved in a mineral oil. water in an amount to constitute the discontinuous phase of the water-in-oil emulsion and having an insoluble grease forming metal hydroxide dispersed throughout in amount suflicient to form a soap with said group memher.

2. Improvement according to claim 1 in which said emulsion contains about 17 to 25% oil, about so to water, and about a to 6% petroleum mahogany sulfonate.

3. Improvement according to claim 2 in which said hydroxide and said petroleum mahogany sulfonate are of the same metal.

4. A metal soap grease, having any water present in the internal phase, produced by the saponification of at least one member of the group consisting of fats and acids thereof dissolved in a mineral lubricating oil with a grease forming metal hydroxide dispersed throughout a water-in-oil emulsion containing a petroleum mahogany sulfonate.

5. An emulsion for the saponification of at least one member of the group consisting of a fat and an acid thereof dissolved in a mineral lubricating oil, which comprises a water-in-oil emulsion, containing a petroleum mahogany ulfonate dissolved in a mineral oil, water in an amount to constitute the discontinuous phase of the water-in-oil emulsion, and an insoluble grease forming metal hydroxide dispersed throughout in amount sufilcient for the saponiflcation.

6. An emulsion according to claim 5 in which said petroleum mahogany sulfonate is present in amount from about 3 'to 6%, said oil being present in amount from about 17 to 25%, and said water being present in amount from about 30 to 60%.

7. An emulsion according to claim 6 in which said petroleum mahogany sulfonate and said hydroxide are of the same metal.

8. An emulsion according to claim 7 in which said metal is at least one member of the group consisting of calcium, lithium, barium and strontium.

JACOB FAUST.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,111,907 Zimmer Mar. 22, 1938 2,265,791 Zimmer Dec. 9, 1941 2,343,737 Beerbower Mar. 7, 1944 2,383,904 Zimmer Aug. 28, 1945 2,394,907 Gallay et al Feb. 12, 1946 2,398,075 Brunstrum Apr. 9, 1946 2,425,174 Carmichael Aug. 5, 1947 2,485,861 Campbell Oct. 25, 1949 2,535,101 Sproule et al. Dec. 26, 1950 

1. IN THE METHOD FOR THE PRODUCTION OF LUBRICATING GREASE BY SAPONIFICATION, THE IMPROVEMENT WHICH COMPRISES INTIMATELY CONTACTING A MINERAL LUBRICATING OIL, CONTAINING A SOLUTION OF AT LEAST ONE MEMBER OF THE GROUP CONSISTING OF FATS AND ACIDS THEREOF, WITH AN EMULSION, SAID EMULSION BEING A WATER-IN-OIL EMULSION CONTAINING A PETROLEUM MAHOGANY SULFONATE DISSOLVED IN A MINERAL OIL, WATER IN AN AMOUNT TO CONSTITUTE THE DISCONTINUOUS PHASE OF THE WATER-IN-OIL EMULSION AND HAVING AN INSOLUBLE GREASE FORMING METAL HYDROXIDE DISPERSED THROUGHOUT IN AMOUNT SUFFICIENT TO FORM A SOAP WITH SAID GROUP MEMBER. 